The Ram Island Ledges are a series of stone ledges, some of which break the waters at the southern end of Casco Bay, a short way south of Cushing Island. In 1855 an iron spindle was erected to protect sailors from these dangerous underwater ledges. The ledge continued to be the site of repeated shipwrecks. On February 24, 1900 the Allan Line steamship Californian (formerly named the State of California) ran aground on the ledge while en route from Portland to Glasgow, Scotland via Halifax, Nova Scotia. As a result of that accident, the United States Congress appropriated funds to build a lighthouse.
Construction began on May 1, 1903 and was completed in 1905